From Nicolas Brodu, new faster osg::Quat::makeRotate(Vec3d,Vec3d) implmentation.

From Robert Osfield, modes to osg::Quat to keep the original implmentation around
as makeRotate_original(,) and added tests into osgunittest to test the new
methods provide equivilant results to the original implemementation.  The
orignal implementation will be removed once the new method is more widely tested.

include/osg/Quat

@@ -343,6 +343,8 @@ class SG_EXPORT Quat
             are co-incident or opposite in direction.*/
         void makeRotate( const Vec3d& vec1, const Vec3d& vec2 );
     
+        void makeRotate_original( const Vec3d& vec1, const Vec3d& vec2 );
+
         /** Return the angle and vector components represented by the quaternion.*/
         void getRotate ( value_type & angle, value_type & x, value_type & y, value_type & z ) const;